部分亚硝化-厌氧氨氧化协同反硝化处理生活污水脱氮除碳

Partial Nitritation and Anaerobic Ammonia Oxidation Synergistic Denitrification to Remove Nitrogen and Carbon from Domestic Sewage

采用SBR-ASBR组合工艺处理实际生活污水,SBR中考察缺氧/好氧时间比及温度对部分亚硝化(partial nitritation,PN)的作用,ASBR中研究COD/NO_(2)^(-)-N(C/N)对厌氧氨氧化(anaerobic ammonium oxidation,ANAMMOX)协同反硝化脱氮除碳的影响.(1)控制温度为25℃,在缺氧/好氧时间比为30 min∶30 min,单周期交替3次时,NO_(2)^(-)-N积累率(NiAR)于第22 d为98.06%,比亚硝态氮产生速率(SNiPR,以N/VSS计)为0.28 g·(g·d)^(-1),同步硝化反硝化去除的TN和COD分别为12.29mg·L^(-1)和110.36 mg·L^(-1).(2)在缺氧/好氧时间比为30 min∶30 min下,温度为15℃时,丝状菌大量繁殖,污泥活性和沉降性变差;温度为30℃时,NH_(4)^(+)-N转化为NO_(2)^(-)-N比例为86.83%,造成出水NH_(4)^(+)-N浓度过低,不能为厌氧氨氧化提供合适基质浓度;温度为25℃时,出水NH_(4)^(+)-N和NO_(2)^(-)-N浓度分别为31.58 mg·L^(-1)和35.04 mg·L^(-1),匹配厌氧氨氧化基质比.(3)组合工艺脱氮性能良好,出水TN、NH_(4)^(+)-N和COD浓度分别稳定在13.13、4.83和69.96 mg·L^(-1),去除率分别为83.10%、93.64%和75.11%.调节ASBR进水C/N为2.5、2.0和1.5时,C/N为2.0时厌氧氨氧化协同反硝化脱氮除碳性能最佳,出水NH_(4)^(+)-N、NO_(2)^(-)-N、NO_(3)^(-)-N和COD分别为0.09、0.25、1.04和32.73 mg·L^(-1).

A sequencing batch reactor-anaerobic sequencing batch reactor(SBR-ASBR)process was used to treat domestic sewage.In the SBR,the effects of the anoxic/aerobic time ratio and temperature on the realization of partial nitritation(PN)were investigated.In the ASBR,the effects of different COD/NO_(2)^(-)-N(C/N)ratios on the removal of nitrogen and carbon using anaerobic ammonia oxidation(ANAMMOX)and denitrification were studied.The results illustrated that:(1)After three single cycles and on the 22nd day,the NO_(2)^(-)-N accumulation rate(NiAR)was 98.06%,and the nitrate nitrogen generation rate(SNiPR,calculated as N/VSS)was 0.28 g·(g·d)^(-1),and simultaneous nitrification and denitrification removal the TN and COD were 12.29 and 110.36 mg·L^(-1),respectively(temperature=25℃,anoxic/aerobic time ratio=30 min:30 min).(2)At an anoxic/aerobic time ratio of 30 min:30 min,the filamentous sludge bulked,the sludge activity decreased,and sludge settleability was poor at 15℃.Furthermore,the conversion rate of NH_(4)^(+)-N to NO_(2)^(-)-N was 86.83%,indicating that the effluent NH_(4)^(+)-N concentration was too low to provide suitable matrix concentrations for ANAMMOX at 300 C.The effluent concentrations of NH_(4)^(+)-N and NO_(2)^(-)-N were 31.58 mg·L^(-1)and 35.04 mg·L^(-1),respectively,matching the ratio of the ANAMMOX substrate at 25℃.(3)The SBR-ASBR combined process showed good denitrification performance;the effluent TN,NH_(4)^(+)-N,and COD concentrations were stable at 13.13,4.83,and 69.96 mg·L^(-1),respectively,and the removal rates were 83.10%,93.64%,and 75.11%,respectively.When the influent C/N of the ASBR was 2.5,2.0,and1.5,respectively,anaerobic ammonia oxidation and denitrification showed the best performance with respect to nitrogen and carbon removal with a C/N of 2.0.The effluent NH_(4)^(+)-N,NO_(2)^(-)-N,NO_(3)^(-)-N,and COD were 0.09,0.25,1.04,and 32.73 mg·L^(-1),respectively.